package com.csdj.server.controller;

import com.google.code.kaptcha.impl.DefaultKaptcha;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.imageio.ImageIO;
import javax.imageio.ImageWriter;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.image.BufferedImage;
import java.io.IOException;

/**
 * @Author xyx
 * @Date 2022/12/15 10:45
 * @ClassName: CaptchaController
 * @Description: 提供验证码生成接口
 * @Version 1.0
 */
@Api(tags = "验证码的控制类")
@RestController
public class CaptchaController {

    @Autowired
    private DefaultKaptcha defaultKaptcha;

    /**
     * produces 返回数据类型
     * @param request
     * @param response
     */
    @ApiOperation(value = "生成验证码")
    @GetMapping(value = "/captcha",produces = "image/jpeg")
    public void captcha(HttpServletRequest request, HttpServletResponse response){
        // 定义response输出类型为image/jpeg类型
        response.setDateHeader("Expires", 0);
        // Set standard HTTP/1.1 no-cache headers.
        response.setHeader("Cache-Control", "no-store, no-cache, must-revalidate");
        // Set IE extended HTTP/1.1 no-cache headers (use addHeader).
        response.addHeader("Cache-Control", "post-check=0, pre-check=0");
        // Set standard HTTP/1.0 no-cache header.
        response.setHeader("Pragma", "no-cache");
        // return a jpeg
        response.setContentType("image/jpeg");
        //-------------------生成验证码 begin --------------------------
        //获取验证码内容
        String text = defaultKaptcha.createText();
        System.out.println("验证码内容:"+text);
        //将验证码存放到session中
        request.getSession().setAttribute("captcha",text);
        //根据 验证码内容 生成 图片
        BufferedImage image = defaultKaptcha.createImage(text);
        ServletOutputStream outputStream = null;
        try {
            outputStream = response.getOutputStream();
            //通过 imageIo 流 以jpg格式 把图片验证码写入到 servlet 输出流中
            ImageIO.write(image, "jpg", outputStream);
            outputStream.flush();
        } catch (IOException exception) {
            exception.printStackTrace();
        }finally {
            //如果 outputStream 未关闭 就执行 outputStream.close()
            if(null != outputStream){
                try {
                    outputStream.close();
                } catch (IOException exception) {
                    exception.printStackTrace();
                }
            }
        }

    }

}
